High Adsorption Ability Research Articles

Adsorption and catalytic degradation by CoFe2O4 coated on metal–organic framework for the removal of 4-nitrophenol and 2,4-dichlorophenol

4-nitrophenol (4-NP) and 2,4-dichlorophenol (2,4-DCP) contaminated wastewater have attracted attention for their genotoxic and carcinogenic hazards. The magnetic MIL-101/CFO was constructed by synergistically integrating porous/hydrophilic/π-conjugated MIL-101(Cr) and CoFe2O4. The nanocomposites markedly accelerated the catalytic reaction activity. The BET characterizations reveal the nanocomposites had a larger specific surface area and pore volume in comparison to the individual CoFe2O4. The composite was employed to evaluate the adsorption and peroxymonosulfate (PMS)-activated ability of 4-NP and 2,4-DCP elimination. The adsorption equilibrium could be achieved within 60 min, following the pseudo-second-order kinetic model and the Langmuir isotherm model. The nanocomposites (0.2 g·L−1) achieved exceeding 96 % decomposition efficiencies toward 4-NP and 2,4-DCP (0.1 g·L−1) after 15 min by PMS (5.29 mM) activation. Notably, the reaction system displayed effective catalytic performance across pH 5 − 10 and resistance to the existence of saline ions and humic acid. According to the free radical quenching experiments and electron paramagnetic resonance, the non-radical route dominant by 1O2 and little of HO• and SO4•− were affirmed to participate the reaction. The recyclable MIL-101/CFO/PMS system approached high adsorptive and catalytic ability for phenolics remediation in the environmental application.

Development of a multi-functional naringin-loaded bioglass/carboxymethyl chitosan/silk fibroin porous scaffold for hemostasis and critical size bone regeneration.

Persistent bleeding and limited repair capacity greatly threaten patients with bone destruction. Designing inorganic-organic biomimetic scaffolds with quick hemostasis and osteogenesis functions will solve this problem. A novel degradable and naringin (NG) loaded porous scaffold (SCB-N) based on APTES-modified bioactive glass (ABG), carboxymethyl chitosan and silk fibroin is developed. ABG and NG enhance the strength of the scaffolds. The scaffolds can release NG and bioactive ions (Ca2+ and Si4+), promoting the expression of osteogenesis (OCN, BMP-2), angiogenesis (VEGF), and neurogenesis (TB3, GFAP) genes in bone mesenchymal stem cells (BMSCs) and the related proteins (OCN, BMP-2, VEGF, GFAP). When implanting the scaffolds in rat cranial critical size defects, all scaffolds exhibit good compatibility, and SCB-N2 (with ABG and 1mg/mL NG) group significantly promotes new bone regeneration and the formation of M2-type macrophages. Transcriptome sequencing results confirmed the osteogenic differentiation of BMSCs stimulated by SCB-N2 scaffolds is mainly regulated through MAPK and Wnt signaling pathways. Moreover, SCB-N2 group demonstrates quick hemostasis in vitro and in vivo due to the high adsorption ability and Ca ions release. The novel bionic scaffolds loaded with ion/traditional Chinese medicine monomer, possess the capabilities of hemostasis, neurovascularization, osteogenesis and immunomodulation, therefore exhibiting potential in bone repair.

Biosorption of petroleum compounds from aqueous solutions using walnut shells

Herein, a walnut shell as a biosorbent was applied to remove petroleum compounds from the water medium. The characterization analyses of the walnut shells showed the macro-mesopore structure of the walnut shells, a specific surface area of 26 m2/g, and the presence of various functional groups (-OH, -COOH, -C = O). The CCD design showed that the walnut shell can remove 84.43% of petroleum compounds at pH = 3 (the optimum pH), adsorbent dosage: 2 g/L, and initial concentration of petroleum compounds: 550 mg/L. The study of kinetics and adsorption equilibrium indicated matching the experimental data with the pseudo-second-order kinetic model and Freundlich equilibrium isotherm, respectively. The maximum adsorption ability of walnut shell was 3038.29 mg/g at 45 °C. The ability to regenerate and reuse the walnut shell was investigated in 6 cycles, and the results showed a 21% decrease in adsorption ability after 6 cycles. The obtained data showed that the walnut shells could be a promising adsorbent with high adsorption ability toward petroleum components. Also, the walnut shell is a regenerable adsorbent, low-cost, and environmentally friendly, and can be effective in successive cycles. Therefore, this biosorbent can have a superb influence on wastewater treatment technology and possible applications at an industrial scale.

Composite coatings based on silicone-modified polyurethane and marine natural product chlorogentisyl alcohol for marine antifouling

Marine biofouling has a serious impact on marine facilities, and traditional antifoulants may cause secondary pollution to the ocean. As chlorogentisyl alcohol (3-chloro-2,5-dihydroxybenzyl alcohol, CHBA) is a marine natural product with excellent antifouling properties, CHBA and its analogues are prepared and combined with silicone-modified polyurethane (SiPU) for development of potential green composite coatings for marine antifouling. Lubricant polydimethylsiloxane and antifoulant CHBA endow the composite material with antifouling properties under dynamic and static conditions, respectively. CHBA is steadily released from the composite coating at a rate of 28 μg/(cm2·d). As one of the CHBA/SiPU composite coatings, SiPU-3 exhibits inspiring activities against Escherichia coli (Gram-negative bacteria), Staphylococcus aureus (Gram-positive bacteria) and Vibriofischeri (marine bacteria), with all inhibition rates exceeding 90.0 %. This composite coating has high antiprotein adsorption ability and algal inhibition rate, showing desirable antifouling performance for up to 90 d in seawater. This work will provide new possible considerations in the development of marine antifouling coatings using marine natural antifoulants.

The impact of bedding planes on microwave-induced damage in rock at the field scale: a numerical model

The feasibility of microwave heating-assisted rock breakage technology in geotechnical engineering has been widely explored. However, the limited knowledge of the impact of the contrast properties between different bedding planes and outer formation stresses limits its application at the field scale. In this work, the mechanics of mineral processing, rock breakage, and unconventional gas and oil exploitation were first characterized. A coupled model is subsequently proposed to govern the coupling process of microwave heating and induce inhomogeneous deformation and stress in various bedding planes. Three stress forms are considered in this approach: horizontal stress, normal stress, and shear stress. With the assistance of the finite element method, the stress conditions of bedding planes composed of rock under free swelling, constant stress, and constant volume were addressed. A bedding plane characterized by high microwave adsorption ability is usually compressed by a bedding plane characterized by low microwave adsorption ability. The bedding ore is under the condition of free swelling during mineral processing, whereas in the remaining two scenarios, the bedding rock is stress controlled. The tensile and compressive stresses can reach their maximum values under the condition of free swelling. The outer formation stress reduces the values of tensile and compressive stresses but has little impact on the shearing stresses. Additionally, this work provides criteria for defining an a priori evaluation of the effectiveness of microwave treatment of bedded ore and rock for different geotechnical engineering applications.

Bimetallic Sulfide Hollow Nanocubes Heterostructure Promotes Dual Coupling of Conversion and Alloying/Dealloying Reactions to Achieve Durable Potassium-Ion Battery Anode.

Conversion and alloying-type transitional metal sulfides have attracted significant interests as anodes for Potassium-ion batteries (PIBs) and Sodium-ion batteries (SIBs) due to their high theoretical capacities and low cost. However, the poor conductivity, structural pulverization, and high-volume expansions greatly limit the performance. Herein, Co1-xS/ZnS hollow nanocube-like heterostructure decorated on reduced graphene oxide (Co1-xS/ZnS@rGO) composite is fabricated through convenient hydrothermal and post-heat vulcanization techniques. This unique composite can provide a more stable conductive network and shorten the diffusion length of ions, which exhibits a remarkable initial charge capacity of 638.5mA h g-1 at 0.1 A g-1 for SIBs and 606mA h g-1 at 0.1 A g-1 for PIBs, respectively; It is worth noting that the composite presents remarkable long stable cycle performance in PIBs, which initially delivered 274mA h g-1 and sustained the charge capacity up to 245mA h g-1 at high current density of 1 A g-1 after 2000 cycles. A series of in situ/ex situ detections and first principle calculations further validate the high potassium ions adsorption ability of Co1-xS/ZnS anode materials with high diffusion kinetics. This work will accelerate the fundamental construction of bimetallic sulfide hollow nanocubes heterostructure electrodes for energy storage applications.

Ultrathin 2D-2D MXene-LDH Interlayer with High Polysulfide Adsorption Ability for Advanced Li-S Batteries.

Lithium-sulfur (Li-S) batteries are considered as promising energy storage systems due to the high energy density of 2600 W h kg-1. However, the practical application of Li-S batteries is hindered by the inadequate conductivity of sulfur and Li2S, as well as the shuttle effect caused by polysulfides during the charge-discharge process. Introducing a conductive interlayer between the cathode and the separator to physically resist polysulfides represents an effective and straightforward approach to mitigate the shuttle effect in Li-S batteries. In this paper, an ultrathin (<1 μm) 2D-2D MXene-LDH interlayer with high polysulfide adsorption ability was introduced to Li-S batteries. The synergistic effect between MXene and layered double hydroxide greatly improved the adsorption effect of the interlayers: the conductive Ti3C2Tx MXene chemically adsorbs polysulfides and promotes their fast transfer, and the NiCo-LDH alleviates the restack of MXene and facilitates Li+ diffusion. After inserting the MXene-LDH interlayer, the Li-S batteries exhibit an enhanced specific capacity of 1137.6 mA h g-1 at 0.1 C and retain 622.6 mA h g-1 after 100 cycles. The ultrathin 2D-2D interlayer offers a feasible way for the development of highly efficient and lightweight interlayers in Li-S batteries.

Hydration and microstructure formation of magnesium oxysulfate (MOS) cement regulated by sepiolite with high adsorption ability

Magnesium oxysulfate (MOS) cement is a potential low-carbon cementitious material with its characteristic depending on the reaction between light-burned magnesia (LBM) and MgSO4 solution. This work aimed to elucidate the effect of sepiolite with high adsorption ability on regulating the reaction within MOS cement. Replacement levels of LBM by sepiolite at 2 and 5 wt% were adopted. Hydration kinetics, microstructure, phase composition and compressive strength of MOS cement without and with sepiolite were studied. Results showed that adding sepiolite into MOS cement adjusted the ion distribution at the early hydration stage and promoted the reaction with an early onset of heat flow peaks. The presence of sepiolite refined the morphology of formed needle-like 5 Mg(OH)2·MgSO4·7H2O (517 phase) and strengthened the bond water within its structure. The high adsorption ability of sepiolite enabled the nucleation of 517 phase and amorphous phase onto its surface. Sepiolite also densified the poorly hydrated regions by tightly combining with the incompletely hydrated MgO grains. Consequently, compressive strength of MOS cement under air curing was improved after adding sepiolite.

Bionanocomposite materials for electroanalytical applications: current status and future challenges.

Bionanocomposites are materials composed of particles with at least one dimension in the range of 1-100 nm and a constituent of biological origin or biopolymers. They are the subject of current research interest as they provide exciting platforms and act as an interface between materials science, biology, and nanotechnology and find applications in disciplines such as electrochemistry, biomedicine, biosorption, aerospace, tissue engineering and packaging. They have different properties such as high conductivity, thermal stability, electrocatalytic ability, biocompatibility, adsorption ability and biodegradability, which can be tuned by their preparation methods, functionalities and applications. However, depending on the objective or the goal of a research project, specific preparation and characterization of bionanocomposites can be undertaken to understand the behavior and confirm the applicability of a bionanocomposite in a given field. Like in electroanalysis applications, electrode materials should be porous (meso- and macro-porosities), having large specific area (at least having a Brunauer-Emmett-Teller surface of 200 m2 g-1), higher stability over time with acceptable power recovery between 95% and 105%, good electrocatalytic ability, and be a good absorbent and a good conductor of electricity (that is to say, it facilitates the transfer of electrons from the solution to the surface of the electrode and vice versa). The present review focuses on the most used method of preparation of bionanocomposites with the critical aspect and their physicochemical and electrochemical characterization techniques, and finally, the practical situations of application of bionanocomposite materials as modified electrodes for electroanalysis of several groups of analytes and a comparison with non-bionanocomposite electrodes are discussed. The future scope of bionanocomposites in the field of electroanalysis is also addressed in this review. But before that, a general overview of bionanocomposite materials in relation to other types of materials is presented to avoid any misunderstanding.

Preparation of low-cost sludge-based highly porous biochar for efficient removal of refractory pollutants from agrochemical and pharmaceutical wastewater

Producing a high-performance sludge biochar through a feasible method is a great challenge and is crucial for practicability. Herein, we reported a highly porous sludge biochar synthesized from agrochemical-pharmaceutical and municipal sludge blends through a novel pyrolysis-acid treatment-post pyrolysis method. The optimized biochar named ASMS91 obtained interconnected pores with a total pore volume of 0.894 cm3/g and a surface area of 691.4 m2/g through extended acid wash and subsequent post-pyrolysis, which is superior to non-activated sludge biochar. ASMS91 removed 45.3 % of wastewater COD (156 mg/L) in 24 h, which was rapid and higher performance than commercial activated carbon (1000 iodine number). This outstanding performance is due to its high adsorption ability of long-chain aliphatic compounds (e.g., 2,4-Di-tert-butylphenol, neophytadiene and eicosane) into mesopores, which accounts for 71.8 % of pore filling. ASMS91 was highly recyclable, and adsorption was reduced by only 5.3 % after the 4th cycle. It also outperformed other sludge biochar in literature in removing perfluorooctanoic acid (PFOA), 6:2 fluorotelomer sulfonate (6:2 FTS), sulfamethoxazole, methylene blue, and methylene orange. Finally, the feasibility of our proposed method was validated by a brief techno-economic analysis. This feasible approach may support future research regarding sludge valorization and low-cost chemical wastewater treatment.

Removal of contaminants from river Jakara using iron oxide nano particles prepared from Citrullus lanatus fruit waste

Achieving sustainable development requires efficient waste water treatment. Green synthesized iron nanoparticles have attracted much attention as potential catalysts for water remediation in view of their lost cost, high reactivity and good adsorption capacity. This study investigated the applicability of iron oxide nanoparticles synthesized from Citrullus lanatus fruit waste (IONP) in the remediation of contaminated water samples that were collected from River Jakara in Kano State Nigeria. The prepared nanoparticle was characterized using Brunauer–Emmett–Teller (BET) surface area, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA). The BET results revealed that IONP have large surface area and are nanometer sized particles. SEM analysis indicated that the adsorbent contain microsphere which might have facilitated the efficient purification of the river water while TGA study revealed that the adsorbent exhibited a three step decomposition process. Data obtained from XRD indicated that the synthesized adsorbent is of high purity and crystalline in nature with an average particle size of 17 nm. Results obtained after treatment of the river water with the adsorbent gave enhanced values of Total Dissolved Solids, Turbidity, Chemical Oxygen Demand, Dissolved Oxygen, phosphate and pH; thus confirming the high adsorption ability of the prepared nanoparticles. The percentage removal of Ni(II) Pb (II) and Cd (II) ions in the river water by IONP was found to depend on adsorbent concentration, agitation time and pH. The adsorption process of these metal ions onto the adsorbent was best described by the Langmuir isotherm model and followed pseudo second order kinetics. The regeneration stability of the adsorbent was adequate when treated with the heavy metals ions at optimum conditions. The nanoparticle synthesized from Citrullus lanatus waste was found to be an efficient and environmentally friendly alternative for treatment of contaminated water.

Magnetically nanorized seaweed residue for the adsorption of methylene blue in aqueous solutions.

The cost-effective and green separation of dye pollutants from wastewater is of great importance in environmental remediation. Industrial seaweed residue (SR), as a low-cost cellulose source, was used to produce carboxylated nanorized-SR (NSR) via oxalic acid (OA)-water pretreatments followed by ultrasonic disintegration. Fourier transform infrared spectroscopy, X-ray polycrystalline diffraction, nitrogen isotherms, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, X-ray photoelectron spectrometry, particle charge detection, zeta potential and retro titration experiments were utilized to explore the physiochemical properties of samples. The NSRs with carboxyl content of 4.58-6.73 mmol g-1 were prepared using 10-60% OA-water pretreatment. In the case of 20% OA-water pretreatment, the highest NSR yield (73.9%) and nanocellulose content (80.2%) were obtained. Through self-assembly induced by the electrostatic interaction, magnetic NSR composite adsorbents (MNSRs) were prepared with the combination of NSR and Fe3O4 nanoparticles (NPs). The carboxylated NSR with negative charge demonstrated good affinity for Fe3O4 NPs. The Fe3O4 NPs were perfectly microencapsulated with the NSR when the NSR/Fe3O4 mass ratio was higher than 1/1. The adsorption properties of the MNSR for methylene blue (MB) removal from aqueous solution were investigated. The adsorbent with NSR/Fe3O4 mass ratio of 1/1 (MNSR1/1) exhibited optimum performance in terms of the magnetic properties and adsorption capacity. The MNSR1/1 showed high adsorption ability in a pH ≥7 environment. According to the Langmuir fitting, the maximum adsorption capacity of MNSR1/1 for MB reached 184.25 mg g-1. The adsorption of MB complies with the pseudo-second-order kinetic model. MNSR1/1 still maintained good adsorption properties after the fifth cycle of adsorption-desorption. MNSR1/1 could selectively adsorb cationic dye (i.e., MB and methyl violet) from wastewater, with hydrogen bonding and electrostatic interaction as the main force.

Facile fabrication of cyclotriphosphazene crosslinked quercetin hollow nanocapsules by dual catalyst strategy for superfast and efficient removal of crystal violet over a wide pH range

A novel cyclotriphosphazene crosslinked quercetin (QuH) nanoadsorbent was manufactured at room temperature through precipitation copolycondensation between quercetin and hexacyclotriphosphazene (HCCP) with the help of dual catalyst. The obtained QuH had a hollow porous structure with specific surface area of 30.18 m2 g−1, an average diameter of 178 nm, and a huge negative surface charge. The adsorption efficiency of QuH was evaluated using water sample polluted with cationic dye crystal violet (CV). Results revealed that the QuH nanoadsorbent delivered an amazing adsorption amount of 840 mg g−1 within one minute and an equilibrium adsorption capacity of 1159 mg g−1 in 120 min for CV at 298.15 K and an initial CV concentration of 300 mg L−1. Moreover, the nanoadsorbent kept a high adsorption ability for CV over a wide pH range of 3–9. The coexisting ion Na+ could promote the CV adsorption, whereas Ca2+ inhibited the CV adsorption. The retention of adsorption capacity could be up to 96 % after five cycles. The superior adsorption performance of QuH for CV was proposed to be the collaborative contribution of electrostatic interaction, ion exchange, hydrogen bonding, π-π stacking and pore filling effect based on the study of adsorption kinetics, isotherm, thermodynamics, and mechanism analysis.

Highly permeable carbon nanotube membranes for efficient surface water treatment through separation and adsorption–electrochemical regeneration

Membrane-based processes feature many advantages for surface water treatment over other technologies; however, the trade-off between membrane selectivity and permeability usually results in the failure to obtain high-quality filtrate at a high permeance. In this study, we report a highly permeable sodium alginate/glutaraldehyde cross-linked carbon nanotube (CNT/SA-GA) membrane with high adsorption ability for surface water treatment. The CNT/SA-GA membranes have a well-formed hollow fiber morphology and good conductivity of 166–261 S/m. They could reject >98 % of large-sized molecules (e.g., Alcian Blue 8GX and Congo Red) at high permeances of 137–227 L/(m2·h·bar). Moreover, they could remove ~100 % of smaller molecules (e.g., Rhodamine B (RhB)) through dynamic adsorption with a capacity of ~57.3 mg/g. Benefiting from their good conductivity, the CNT/SA-GA membranes could easily decompose the pollutants after adsorption saturation through electrochemical oxidation and then regenerated themselves. Though the switch between adsorption and electrochemical oxidation (2.0 V), the CNT/SA-GA membranes could remove ~100 % RhB at a high permeance of 342 L/(m2·h·bar), which is one order of magnitude higher than those of nanofiltration membranes. When used for surface water treatment, the CNT/SA-GA membranes exhibited a much higher TOC removal rate than commercial poly(acrylonitrile) (PAN) membranes (56.2 % vs. 7.2 %). LC-MS/MS analysis showed that many small molecules such as caffeine could be effectively removed by the CNT/SA-GA membranes. In addition, they exhibited a higher fouling resistance than PAN membranes, evidenced by their lower permeance decline ratio (10.1 % vs. 43.7 %). This study will promote the development and applications of the CNT-based membranes for water purification.

Locust leaves-derived biochar coupled CuxO composites for efficient electrocatalytic CO2 reduction

The electrochemical CO2 reduction reaction (CO2RR) to obtain high-valued product is considered to be a promising strategy for greenhouse effect mitigation. However, the development of low-cost electrocatalysts with excellent electrocatalytic performance is necessary. In this study, we developed a serials of locust leaves-derived CuxO@C composites with large surface area and high CO2 adsorption ability. Among them, the CuxO@C-2 with optimal C content (0.10 g) displays the highest FEC2H4 of 41.3 % at −1.08 V vs. RHE, which is 1.7 times higher than that of pure CuxO sample. The enhanced performance for CO2RR may be attributed to the large BET surface area, improved adsorption ability of CO2 and exposed abundant active sites. The work provides a feasible strategy for configuring CuxO-based materials with high adsorption capacity and more reaction activity sites.

A new nanocomposite as adsorbent and catalyst for enhanced removal of methylene blue

In this study, we present, for the first time, the preparation and characterization of a few-layer graphene (FLG)/Fe3O4/Ag nanocomposite functionalized with polyacrylic acid (PAA) polymer for the removal of methylene blue (MB). X-ray Powder Diffraction (XRD) analysis confirmed the coexistence of Fe3O4 and Ag nanoparticles. The results demonstrate a high adsorption ability (qmax 141.60 mg/g) of the nanocomposites, achieving 98% removal of MB dye within 40 min at a concentration of 50 mg/L, with a nanoadsorbent amount of 100 mg. Furthermore, the findings indicate that the FLG/Fe3O4/Ag@PAA adsorbent maintains high dye removal efficiency over four consecutive cycles. The FLG/Fe3O4/Ag@PAA nanocomposites exhibit significantly enhanced catalytic reduction activity on organic pollutants. The reduction of MB can be completed in 300 s in the presence of NaBH4 as a reducing agent, using 5 mg of nanocatalyst and a concentration of MB dye of 50 mg/L. These results suggest that the nanocomposite can serve not only as an adsorbent but also as a promising catalyst for the reduction of organic dyes.

Synthesis of Mesoporous Silica from Palm Oil Boiler Ash (MS-POBA) with Addition of Methyl Ester Sulfonate as a Template for Free Fatty Acid Adsorption from Crude Palm Oil (CPO)

The synthesis of mesoporous material by utilizing palm oil boiler ash (POBA) waste as the silica source and methyl ester sulfonate (MES) surfactant as the template for a high-porosity was investigated for free fatty acids (FFA) adsorption. The research was initiated with silica extraction from POBA by sodium hydroxide addition through the sol-gel precipitation method. Silica modification was carried out with MES surfactant and 3-aminopropyltrimethoxysilane (APTMS) as the co-structure-directing agent (CSDA) in different calcination temperatures. Mesoporous silica-POBA (MS-POBA) free template had a surface area, pore diameter, and pore volume (41.033 m2/g, 4.180 nm, and 0.250 cm3/g) lower than MS-POBA with the template (71.0147 m2/g, 7.923 nm, and 0.524 cm3/g). The ability of MS-POBA to adsorb FFA reached its optimum conditions with an adsorption time of 20 min and an adsorbent dosage of 0.24 g. The FFA removal by MS-POBA with the template was found to have higher adsorption ability, which was 35.54%, compared to the MS-POBA free template of 26.68%. The high porosity of MS-POBA with a template makes the FFA adsorption capacity of this material higher than MS-POBA free template.

Synthesizing hard carbon anodes for potassium-ion batteries from black liquor and deinking sludge

Porous hard carbon anodes, with large interlayer space and high adsorption ability, can offer much better cycle stability and higher discharge capacity for potassium-ion batteries compared to commercial graphite anodes. However, most commercial hard carbons are synthesized from relatively expensive high-molecular polymers. In this study, pulping and papermaking wastes were utilized as precursors for producing hard carbons and pore-enlarging agent, respectively. Specifically, after thorough mixing through ball milling, black liquor solids and deinking sludge were utilized to produce porous hard carbon anodes via co-pyrolysis. The results show that direct pyrolysis of black liquor can produce hard carbons efficiently, eliminating the need to extract lignin from black liquor. Moreover, it is shown that the pore-enlarging agent derived from deinking sludge can enlarge much portion of pores on hard carbons, resulting in abundant mesopores. Electrochemical tests demonstrate that the synthesized porous hard carbon anodes can achieve highest specific capacity of 303.5 mAh g−1 at 100 mA g−1 using a 1.0 M potassium hexafluorophosphate electrolyte in a mixture of diethyl carbonate and ethylene carbonate. Additionally, the synthesized porous hard carbon anodes exhibit low average capacity decay per cycle of 0.06 % at 100 mA g−1 when tested with a 1.0 M potassium bis(fluorosulfonyl)imide electrolyte in the same solvent mixture after 500 cycles. Therefore, recycling black liquor and deinking sludge to produce porous hard carbon anodes for potassium-ion batteries is a promising approach for environmental and energy sustainability.

Shuttle-free zinc–iodine batteries enabled by a cobalt single atom anchored on N-doped porous carbon host with ultra-high specific surface area

Aqueous zinc‑iodine batteries are favorable solutions for grid-level energy storage owing to their cost-effective components and intrinsic safety. Nevertheless, the sluggish conversion kinetics and polyiodide shuttle effect have significantly hindered their practical applications. Herein, a Co single atom anchored on N-doped porous carbon nanosheets (Co-SAs@NPC) was produced through an efficient molten-salt engaged pyrolysis process and further utilized as the iodine host for aqueous zinc-iodine batteries. The large specific surface area (1741 m2 g−1) combined with abundant heteroatom-containing functional groups can afford a tight physical and chemical confinement towards iodine species. Meanwhile, the presence of Co single atoms exhibits high electrocatalytic activity towards I2 reduction reactions. According to the experimental results and DFT theoretical calculations, the resulting Co-SAs@NPC can simultaneously offer generous electrochemical active sites and electrocatalytic activity, which displays a high adsorption ability towards iodide species and boost the reversible redox reactions between iodine and iodides. Consequently, the as-assembled zinc-iodine batteries with Co-SAs@NPC/I2 cathodes can deliver a high specific capacity (295 mA h g−1 at 0.3 A g−1), good rate performance (199 mAh g−1 at 20 A g−1), and long cyclic stability over 10,000 cycles. Additionally, the absence of polyiodide shuttle was analyzed by a series of ex-situ spectrum analyses.

Flower shaped Zn2In2S5/FeIn2S4 as a promising S-Scheme heterojunction photocatalyst for superior ciprofloxacin removal

In recent years, refractory pharmaceutical pollutants have emerged as a major environmental and public health concern. An interesting strategy that has recently emerged is photocatalysis, which involves directly breaking down these environmental pollutants using visible light. However, the rapid combining of the photogenerated charges is a major issue with this method, leading to instability and low efficiency. This work presents the development of a Zn2In2S5/FeIn2S4 (ZIS-/FIS) heterojunction photocatalyst, which is an effective photocatalyst for the degradation of ciprofloxacin (CIP) when exposed to visible light. When compared to pure ZIS and FIS, the resultant ZIS-/FIS S-type heterojunction shows significantly better visible light-driven photocatalytic performance. Specifically, 20ZIS/FIS catalyst exhibits the highest photocatalytic efficiency for CIP breakdown, reaching 90.03% at 10 mg/L concentration in 120 min. Through scavenging experiments and ESR findings, it has been demonstrated that •O2- and •OH are the primary active species that are involved in the degrading process. The higher adsorption ability, heightened light harvesting, and increased separation rate of carriers that resulted from the synergistic effect of the components are the primary factors that are responsible for the superior removal performance. The results of this work offer a realistic reference for the construction of novel heterojunction photocatalysts for the purpose of maintaining environmental cleanliness.